I. Field of the Invention
The present invention relates generally to an automated system for opening and closing bottom gates on railcars and, more particularly, relates to an automated railcar gate operating system for capstan-operated railcar gates that sequentially locates and opens and closes gate operating capstans of railcars on the fly as the car move along across a cargo receiving pit.
II. Related Art
Uni-Trains, many containing 100 or more cars of identical or a variety of sizes and types, have long been acknowledged as desirable and efficient carriers of bulk raw materials such as coal, iron ore, limestone, various finely divided dry bulk agricultural products including grains, etc., and liquid or dry chemicals. These cars are typically filled from above and may be emptied using a rotary car dumper in the case of coal or iron ore. Liquid bulk cargo is typically unloaded by connecting outlets to large hoses with associated pumping equipment and opening bottom drain valves.
Cars shipping bulk agricultural products, for example, however, are bottom emptied into stationary cargo-receiving pits. These cars are provided with a number of spaced bottom discharging hopper bins accessing the main storage volume of the car. These hoppers are closed by horizontal slide gates. When the hoppers are precisely positioned over fixed recessed receiving facilities beneath the railroad track, the gates are opened and the cargo discharged.
In the bottom discharge operation, a connected train engine roughly positions one end of a string of cars to be unloaded close to the unloading facility. However, train engines are not well suited for indexing or precisely positioning individual cars or even sets of cars along the track. Because of this, traditionally, train positioning devices known as railroad car indexers or movers have been built and operated at fixed stations along the tracks to more precisely position cars for unloading operations.
Railroad cars having bottom discharge hopper-type bodies include spaced aligned hoppers which are closed by separate, horizontally disposed gates that are displaced laterally to open and close the bottom of each hopper by drive systems that typically include a rack and pinion mechanism operated by rotating an associated operating rod using an attached capstan. This requires a separate manual operation utilizing a powered gate operator in which a key or gripper device is used to attach to and rotate each of the capstans. This function has long involved the provision of a separately supplied cantilevered gate operator device utilizing a telescoping chuck to engage a capstan of a railroad car gate. The gate operators are typically separately mounted to operate along their own gate operator platform spaced from, but associated with, a railcar indexing system. This has involved a relatively slow and labor intensive operation. The chuck must be adjusted to match the height, depth and rotational position of each capstan.
Attempts have been made to automate the opening and closing of railcar discharge doors using trackside devices mounted on moveable carriages to operate doors located near the bottom of hopper-type railcars. One such system used to address latching, hinged gates is shown in U.S. Pat. Nos. 7,063,022 and 7,178,465. Earlier attempts to automate capstan operators have heretofore not met with much success.
Thus, there remains a need to provide a fully automated bottom discharge gate operating system that addresses rotating capstan-operated bottom discharge gates in commodity carrying railcars. Such a system would be particularly advantageous if it could operate to unload a string of cars into a grain receiving pit “on the fly” while the cars are moved across the pit.